As Sparta already advised: limit your p2p's upstream (and if needed, it's downstream, too), to retain some bandwith for other apps, like mIRC. And don't overdo the number of active connections, if you are using a router in particular.
Please, don't discredit all p2p (and it's users) to possible piracy and abuse. Supporting a p2p client on IRC myself (legal and voluntarily), I'm facing this kind of "blanket judgment" all too often... mIRC and p2p-apps can be used and misused alike - it's been a technical question, and imho it should be treated as one.